Repeating circuit interrupter



April 2, 1968 K. H. DATE REPEATING CIRCUIT INTERRUPTER 2 Sheets-Sheet 1 Filed July 9, 1964 INVENTOR. 47200 71. Date fittormy April 2, 1968 K. H. DATE I 3,376,525

REPEATING CIRCUIT INTERRUPTER Filed July 9, 1964 2 Sheets-Sheet 103" I W w 2% /0 3'1 13/707, 7 m 4% /37 United States Patent 3,376,525- REPEATING CIRCUIT INTERRUPTER Kazuo Henry Date, South Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed July 9, 1964, Ser. No. 381,308 13 Claims. (Cl. 335-26) This invention relates to repeating circuit interrupters and, more particularly, to means for controlling the operating sequence of a repeating circuit interrupter.

It is common practice to protect electrical distribution systems with a variety of protective devices having time current characteristics of dilferent shapes and slopes. For example, such a system may be provided with a repeating circuit interrupter or recloser connected in series with a main line and fuses disposed in feeder lines radiating from the main line. Because the majority of faults in such systems are temporary in nature, and will therefore clear in a relatively short time, it is common to arrange the repeating circuit interrupter to execute a series of rapid opening operations each followed by a reclosing operation wherein the period in which the system remains energized is shorter than the time necessary for the fuse elements to melt. If the fault does not clear during this initial series of rapid operations, it is considered permanent and there follows a second series of opening operations which are time delayed so that the recloser contacts remain closed for periods of sufficient length to melt the fuse element in the faulted feeder line. If the fault is cleared by the melting of a fuse element or for some other reason during any of these successive operations, the recloser closes to maintain power in the main line and in the non-faulted feeder lines. If, on the other hand, fault is not cleared during the series of rapid and retarded opening operations, the recloser automatically locks open to disconnect the main line from the source.

One type of prior art repeating circuit interrupter employs a solenoid having a coil connected in series with the line being protected and a magnetic plunger movable into the coil upon the occurrence of an overload current to open interrupting contacts and to extend a contact closing spring. When the main contacts open, the current through the solenoid coil disappears so that the contact closing spring is then free to return the solenoid plunger to its initial position and to close the interrupting contacts. Such prior art repeating circuit interrupters may also employ a hydraulic integrating mechanism which initiates time delayed operation after an initial plurality of rapid opening operations and which is further operative to prevent reclosure of the main contact if the fault does not clear after a predetermined number of opening and reclosing operations. Integrating mechanisms of this type generally include an integrating piston and a pump mechanism which is operated by the movement of the solenoid plunger to deliver a measured quantity of hydraulic fluid to the integrating piston upon each switch opening operation so that the integrating piston is advanced an incrimental distance toward positions where time delayed operations and lockout are initiated. Because the magnetic plunger moves upwardly through a hydraulic medium, its movement is retarded and this determines the closing time delay of the device.

Should the fault current disappear before the interrupting switch of such prior art devices reaches its fully open position, the closing springs may tend to return the solenoid plunger to its initial position and close the main contacts prematurely. This destroys coordination between the repeating circuit interrupter and other protective devices in the system. In addition, the return of the mag netic plunger to its initial position before its movement 3,376,525 Patented Apr. 2, 1968 into a full switch open position might prevent delivery of the full measured quantity of hydraulic fluid from the pump piston to the integrating piston.

The operating springs of most prior art devices of the series-connected type of repeating circuit interrupters derive their energy from the operation of the series-connected solenoid coil and its associated magnetic plunger. The solenoid coil is connected in series with the line being connected and upon the occurrence of an overload in the system, the plunger is attracted into the coil to extend the operating spring. The energy thus stored in the operating spring must be available to open the main interrupting contacts, to return the solenoid plunger to its initial position and to reclose the main contacts. It can be seen that because the contact closing operation is performed last, sufiicient stored energy may not be available for this purpose.

It is an object of the invention to provide a repeating circuit interrupter with operating sequence control means which insures system coordination.

Another object of the invention is to provide a repeating circuit interrupter having switch means and condition responsive means operable from an initial to a final state upon the occurrence of an abnormal circuit condition and returnable to its initial state upon the disappearance thereof and switch operating means for opening the switch means upon operation of the condition responsive means to its final state wherein the switch means is held in its open position until after the condition responsive means returns to its initial state. Another object of the invention is to provide such repeating circuit interrupters wherein the abnormal condition responsive means is held in its final state until the switch means reaches its open position.

A further object of the invention is to provide a series solenoid-type repeating circuit interrupter with means for preventing return movement of the solenoid plunger before the interrupting switch reaches its fully open position.

It is another object of the invention to provide a series solenoid-operated repeating circuit interrupter with means for preventing the interrupting switch from moving toward a closed position until the solenoid plunger has returned to an initial position.

Yet another object of the invention is to provide a stored energy spring operated repeatingcircuit interrupter with a booster spring assembly which provides additional spring force for the switch closing operation.

These and other objects and advantages of the instant invention will become more apparent from the detailed description of the instant invention taken with the accompanying drawings in which:

FIG. 1 is a side elevational view, with parts broken away, of a repeating circuit interrupter incorporating the instant invention;

FIGS. 2 and 3 are sectional views showing in greater detail the hydraulic portions of the repeating circuit interrupter illustrated in FIG. 1;

FIG. 4 is a side elevational view, partly in section, showing a portion of the operating mechanism according to the instant invention; and

FIGS. 5, 6 and 7 illustrate the operating mechanism in its various positions during switch opening and reclosing operations.

Referring now to the drawings in greater detail, FIG. 1 shows a repeating circuit interrupter or recloser 10 incorporating the instant invention and including a metallic housing or tank 11 'which is closed at its upper end by a gasketed cover 13 from which the internal operating mechanism is suspended on insulating supports 14. The tank 11 is ordinarily filled with dielectric fluid, such as oil, to the level indicated by the dashline 15.

The cover 13 also supports a pair of insulating bushings 16, only one of which is seen in FIG. 1. The bushings 16 extend interiorly of the tank 11 and beneath the oil level 15 for serially connecting the recloser in the system being protected. As seen in FIG. 1, the current path between the bushings 16 and through the recloser 10 constitutes a series circuit through an electromagnetic operating coil 17 and an interrupting switch assembly generally designated by the reference numeral 18.

In order to correlate the various portions of the repeating circuit interrupter 10 shown in FIG. 1, its operation will now be discussed in general terms. Each time an overcurrent occurs in the system being protected, an electromagnetic plunger 19 is attracted downwardly into the series connected operating coil 17 to move an operating rod 20 connected to its lower end into engagement with an operating mechanism 24, causing a movable contact arm 21 to pivot around a fixed shaft 26 and to its open position. With the interrupting switch 18 open, the series coil 17 is de-energized so that the mechanism 24 is free to elevate the electromagnetic plunger 19 and to rotate the contact lever 21 into its closed position.

As will be described more fully hereinbelow, each time the magnetic plunger 19 is depressed upon the occurrence of an abnormal circuit condition, an insulating stem 22 connected to its upper end is operative through the agency of a bell crank 23 to depress a pump piston 25 to thereby deliver a measured quantity of fluid to a hydraulic integrating mechanism 27. Upon each pumping operation, a stem 28 extending outwardly from the integrating mechanism 27 is advanced a predetermined distance toward a trip finger 29. After a predetermined number of such switch opening and reclosing operations the stem 28 will engage the finger 29 to release the overcenter lockout mechanism 30 which, in turn, will engage the bell crank 23 connected to the upper end of stem 22 to depress the magnetic plunger 19' and thereby open the interrupting switch 18 and hold the same open until manually reset.

Certain of the various details of the repeating circuit interrupter just described form no part of the instant invention and, accordingly, will not be discussed in detail, for the sake of brevity. For a more complete description of these details, reference is made to Patent 2,926,228, which is assigned to the assignee of the instant invention.

As seen particularly in FIG. 2, the magnetic plunger 19 descends through a bore 35 formed in a casting 31 which also contains the pump piston 25 and the integrating assembly 27. A dashpot cylinder 37 is provided coaxially with the bore 35 for receiving the magnetic plunger 19 and is formed by the insulating spool 30 upon which the series operating coil 17 is wound. An aperture 40 (see FIG. 1) is provided in the lower end of the dashpot cylinder 37 to allow the operating rod 20 to pass therethrough for engagement with the operating assembly 24 as described hereinabove. The magnetic circuit for the flux emanating from the coil 17 includes the plunger 19, the metallic casting 31, the metallic base plate 32, a metallic plug 39 at the lower end of the dashpot cylinder 37 and metallic support brackets 33 which extend between the casting 31 and the plate 32. The brackets 33 along with metallic rods 34 support the coil 17 and the base plate 32 which, in turn, support the interrupting switch assembly 18 between a pair of vertical insulating plates 36.

The pump piston 25 is disposed for reciprocal movement in a cylinder 40 formed in the casting 31 and has a stem 41 extending upwardly therefrom for engaging a pin 42 carried by one arm 44 of the bell crank 23 which is pivoted about a fixed point 46 beneath the cover 13. The arm 44 of the bell crank 23 is also pivotally connected at 45 to the upper end of the plunger stem 22.

Although the overcenter mechanism 30* will not be discussed in detail, it is sufficient to state that when the stem 28 engages the trip finger 29, the crank 23 will be restrained in its counterclockwise rotated position so that the plunger stem 19 is held in its depressed position whereby the main contacts 18 are locked open.

A semi-circular duct 48 formed in the bottom of the casting 31 connects the lower end of cylinder 40 with the lower end of an integrating cylinder 50 forming a part of the integrating mechanism 27. The duct 48 is sealed by a flat gasket plate 51 and held against the lower end .of the casting 31 by a circular washer plate 52 which is disposed between the spool 38 and the lower surface of a casting 31 and which has an aperture 53 for passage of the magnetic plunger 19.

A discharge port 58 connects a slide valve cylinder 59 with the upper end of the dashpot cylinder 37. When the plunger 19 is attracted downwardly, the fluid in cylinder 37 is displaced through the port 58 into the slide valve cylinder 59. A slide valve 60 is disposed at the upper end of the cylinder 59 and is normally biased against a shoulder 61 by a compression spring 62.

During opening operations of the repeating circuit interrupter 10, fluid pressure developed by the descent of plunger 19 causes a disc valve 64 mounted adjacent the lower surface of the slide valve 60 to close an orifice 63 provided through said valve, so that slide valve 60 is elevated in opposition to a compression spring 62. This opens an escape port 65 which leads from the slide valve cylinder 59 to the open upper end of the integrating cylinder 50 so that fluid from the port 65 is free to discharge into the b d of the fluid within the tank 11.

A ball checkvalve 70 connects the lower end of integrating cylinder 50 to the duct 48 to permit the easy ingress of fluid into cylinder 50 and to prevent the discharge thereof back into the duct 48. The integrating assembly 27 also includes a piston 71 which carries the stem 28 at its upper end and which is biased for return toward the lower end of the cylinder 50' by a return spring 72.

As seen in FIG. 3, elevation of the slide valve 60 also exposes one of a plurality of orifices '74 formed in an orifice plate 75 and which may be rotated into registry with a passage 76 opening into the cylinder 59.

'In order to more fully appreciate the instant invention, the operation of those conventional portions of the recloser 10 which have been mentioned heretofore will now be discussed. Upon the occurrence of an overload current in the coil 17, the plunger 19 will be attracted downwardly through the bore 35 in the casting 31 and into the dashpot cylinder 37. The initial movement of the plunger 19 will be substantially unimpeded because a plurality of axial surface slots 81 formed in the piston 19 allows the fluid from dashpot cylinder 37 to discharge freely along the piston. However, when the piston 19 has descended to the point where the upper ends of the slots 81 move past a shoulder 82 formed in the upper end of the bore 35, the slots 81 will be closed by the walls of said bore, so that retarded descent of the plunger 19 begins. The fluid forced from the dashpot cylinder 37 when the slots 81 are closed passes through the relief port 58 forcing the slide valve 60 upwardly and escapes through the escape port 35.

Downward movement of plunger 19 will also pivot crank 23 counterclockwise to force the link 41 downwardly, thereby moving the pump piston 25 into the pump cylinder 40'. Upon the initial descent of the pump piston, the hydraulic fluid in the lower end of the cylinder 40 will be discharged through a relief opening 84 until the lower end of the piston 25 has been depressed sufficiently to cover this opening. Thereafter, as the piston 25 descends, the fluid in the lower end of cylinder 40 will be delivered to the lower end of the cylinder 50, through the duct 48 and past the ball checkvalve 70. This moves the integrating piston 71 a predetermined distance upwardly against a return spring 72 so that the stem 28 is elevated a predetermined distance toward the trip finger 29 of the lockout mechanism 30.

Referring again to FIG. 1, it can be seen that the lower end of the rod 20 rests'on a roller '99 carried at one end of a triangular member 100, the other end of which is pivotally mounted about a fixed pin 101 which extends between the support plates 36. -A first plunger link 102 is pivotally connected at 103 intermediate the ends of the member 100 and extends generally downwardly therefrom where its opposite end is pivotally connected by a pin 104 to one end of a second plunger link 105. The second plunger link 105 is pivotally mounted near its opposite end to a fixed shaft 106 and carries a latch pin 107 adjacent said opposite end (see FIG. 4). The contact arm 21 is generally elongate and carries the movable contact portion of the interrupter switch 18 at one end and is .pivotally mounted at its other end about the fixed shaft 26 which is disposed adjacent the second plunger link 105. A stored energy main operating spring 108 extends between the pin 104 which pivotally connects the two plunger links 102 and 105 and a pin 110 afiixed intermediate the ends of the contact lever 21.

As seen particularly in FIG. 4, a pair of generally V- shaped catch members 112 and 114 are each pivotally mounted about a common fixed shaft 115 which extends between the plates 36 and which is disposed adjacent the other end of the second plunger link 105. A first spring 116' biases the first catch member 112 clockwise against a stop pin 118 carried by the second plunger link 105 between its fixed pivot shaft 106- 'and the latch pin 107. A second spring 119 urges the second catch member 114 counterclockwise against the latch pin 107.

Returning again to FIG. 1, one arm of a generally T- shap ed member 121 is pivotally mounted on the fixed pin 26 and its other arm carries a pin 122 for receiving one end of a booster spring 124, the other end of which is anchored to a fixed pin 125. The pin 122 also carries a roller 127 which is engaged by a cam member 128 extending downwardly from the second plunger link 105.

When the interrupter switch 18 is in its closed position, shown in FIG. 1, the stored energy main operating spring 108 exerts an upward force on the plunger link 102 to hold the plunger 19 in its elevated position. Upon the occurrence of an overload current in coil 17, plunger 19 is attracted downwardly whereby member 100 is rotated clockwise from its position shown in FIG. 1 to its position shown in FIG. to force the first plunger link 102 downward as the second plunger link 105 pivots counterclockwise about shaft 106. This moves the latch pin 107 carried by the opposite end of the second plunger link 105 generally upward to rotate the second latch member 114 through a slight clockwise angle against spring 119 until the latch pin 107 is opposite a catch 130 formed in one leg of the catch member 114 (see FIG. 4). Upon this event, spring 119 will rotate catch member 114 through a slight counterclockwise angle to latch the pin 107 in the catch 130. In addition, as the second plunger link 105 pivots, the cam 128 acting on the roller 127 will pivot the T-shaped member 121 clockwise to extend the booster spring 124. The shape of the cam 128 is such that the booster spring 124 is not extended until the link 105 approaches its fully rotated position. This insures that the booster spring 124 does not impede the downward travel of the plunger 19 until after the interrupting contacts 18 have begun movement toward their open position. In this way, the extension of the booster springs 124 in no way impedes the opening operation of the circuit interrupter 10. As the second plunger link 105 pivots to its position shown in FIG. 5, the switch arm 21 will initially remain inactive so that the spring 108 will be extended. As the member 100 approaches its final position shown in FIG. 5, the roller 99 impacts a second roller 131 carried about the pin 110 on the switch arm 21 to pivot said switch arm about its fixed shaft 26. Simultaneously, the line of action of spring 108 moves overcenter past the fixed shaft 26, as the plunger link 105 reaches its final position, whereby the switch arm is snapped clockwise from its sition until the plunger 19 reaches its 1 position shown in FIG. 7, whereupon the pin 1.18 carried position shown in FIG. 5 to its position shown in FIG. 6, thereby opening the interrupting contacts 18.

After the interrupting contacts 18 open, the current in coil 17 will disappear so that the magnetic plunger 19 is no longer attracted downwardly. In addition, the spring 108 will exert an upward force on the pin 104 tending to rotate the second plunger link clockwise about shaft 106 and to move the first plunger link 102 upward and to the right as viewed in FIG. 5. Such movement is prevented, however, because of the engagement of the latch pin 107 carried by the plunger link 105 in the catch 1-30 of the member 114.

As the switch arm 21 moves into its fully open position shown in FIG. 6, a transversely extending pin 134, afiixed to arm 21 between roller 131 and movable contact portion of switch 18, will engage the other arm of catch member 114 to rotate the latter through a slight clockwise anlgle against spring 119 and from its position shown in FIG. 5 to its position shown in FIG. 6, whereby the latch pin 107 is released from the catch 130. The plunger link 105 is thereby freed for clockwise rotation from its position shown in FIG. 6 to its position shown in FIG. 7, wherein the plunger 19 is returned to its elevated position by spring 108. It can be seen, however, that this action occurs only when the interrupting contacts 18 are in their fully open position.

In this manner, any premature movement of the plunger linkage to return the plunger to its elevated position is prevented so that a full opening stroke of the interrupting contacts 18 is assured even though the overload current may be interrupted prior to the movement of the switch arm 21 to its fully open position as might occur during a relatively low magnitude fault current.

Referring again to the action of the switch arm 21 as it nears its fully open position, the transverse pin 134 will also engage the upper slanted surface 136 of the other catch member 112 to rotate said catch member counterclockwise as viewed in FIG. 6 and against the action of spring 116. This allows the pin 13 4 to move into a latched position below the catch 137 as the spring 116 returns member 112 to its unrotated position. In this manner, the switch arm 21 is latched against premature movement toward its closed position.

While the switch arm 21 is in its latched position shown in FIG. 6, its lower end will engage a pin extending transversely from the base of the T-shaped member 121. As a result, when the plunger link 105 is released for clockwise rotation to move the cam 128 out of engagement with the roller 127, as seen in FIG. 7, the booster spring 124 will, when released, exert a counterclockwise moment on the switch arm 21. This spring force will supplement that of the main operating spring 108.

The switch arm 21 will be latched in its fully open poinitial uppermost by the link 105 will engage the arm 139 of the catch member 112 rotating it from its position shown in FIG. 6 to its position shown in FIG. 7. This frees the switch arm 21 for counterclockwise rotation about shaft 26 by the main spring 108 and the booster spring 124.

As the pluunger 19 moves out of the dashpot cylinder 37 and into the bore 35 of the casting 31, its movement will become retarded because of the limited clearance space therebetween through which fluid may move into said dashpot cylinder. This retarded movement of the plunger 19 determines the closing time delay of the recloser. In order to obtain the full closing time delay period, it is essential that the interrupting contacts 18 do not close prior to the movement of the plunger 19 to its initial elevated position. In addition, because the plunger 19 is connected to the pump piston 25, it is essential that the plunger move to its fully depressed position before it begins its return movement or else the pump piston may not deliver full measured quantity of hydraulic fluid to the integrating piston 71. As a result of such insuificient pumping action, the stem 28 of the integrating assembly 27 would not engage the trip finger 29 of the lockout assembly 30 after the fourth opening operation as the system design requires.

It can be seen that proper operating sequences are provided by which movement of the plunger 19 is prevented toward its initial, elevated position until the interrupting contacts 18 reach their fully open position and by the catch member 112 which prevents return movement of the interrupting contacts 18 toward their closed position until the plunger linkage reaches its initial position. Thus, the recloser according to the instant invention insures a lockout operation after the desired number of switch opening and reclosing operations and further insures that the closing time delay of the device, which is necessary for coordination with other types of protective devices in the same system, will be of the requisite length. In addition, the recloser according to the instant invention provides sufficient closing force .to insure rapid closing of the interrupting contacts.

While only a single embodiment of the instant invention has been shown and described, it is not intended to be limited thereby but only by the scope of the appended claims.

I claim:

1. A repeating circuit interrupter having switch means, condition responsive means in circuit with said switch means and operable from an initial state to a final state upon the occurrence of an abnormal circuit condition, switch operating means for opening said switch means as said condition responsive means operates to its final state, first means for holding said condition responsive means in its final state, means operatively associated with said switch means for releasing said condition responsive means when said switch means reaches its fully open position, said switch operating means returning said condition responsive means to its initial state, second means for preventing said switch means from moving out of its fully open position and means for releasing said switch means after said condition responsive means returns to its initial state, said switch operating means 'being operative to return said switch means to its closed position.

2. The repeating circuit interrupter set forth in claim 1 wherein said first means comprises latch means for engaging said overload responsive means when the latter is in its final position.

3. The repeating circuit interrupter set forth in claim 1 and including resilient means engageable with said switch means as the latter moves into its fully open position for urging the same toward its closed position in cooperation with said switch operating means.

4. A repeating circuit interrupter having switch means, condition responsive means in circuit with said switch means and operable from an initial state to a final state upon the occurrence of an abnormal circuit condition, switch operating means coupled to said condition responsive means for being charged and for opening said switch means as said condition responsive means operates to its final state, said switch operating means urging said condition responsive means to its initial state when said switch means is open and said switch means to its closed position when said condition responsive means is in its initial state, first means for holding said condition responsive means in its final state, means operatively associated with said switch means for releasing said condition responsive means when said switch means reaches its fully open position so that said switch operating means returns said condition responsive means to its initial state, second means for preventing said switch means from moving out of its fully open position, and means for releasing said switch means after said condition responsive means returns to its initial state, so that said switch operating means returns said switch means to its closed position.

5. A repeating circuit interrupter having switch means,

overload responsive means in circuit wit-h said switch means and movable from an initial position to a final position upon the occurrence of an overload current, spring means for opening said switch means as said overload responsive means moves into its final position, first latch means for holding said overload responsive means in its final position, means operatively associated with said switch means for releasing said overload responsive means when said switch means reaches its fully open position, second latch means for holding said switch means in its fully open position, said spring means returning said overload responsive means to its initial position, and second latch release means for releasing said switch means after said overload responsive means reaches its initial position, said spring means being operative to return said switch means to its closed position.

6. A repeating circuit interrupter having switch means, overload responsive means in circuit with said switch means and movable from an initial position to a final position upon the occurrence of an overload current, stored energy means coupled to said overload responsive means for being charged and for opening said switch means as said overload responsive means moves into its final position, said stored energy means being operative when charged to urge said switch means toward its closed position and said overload responsive means toward its initial position, first means for holding said overload responsive means in its final position, means operatively associated with said switch means for releasing said overload responsive means when said switch means reaches its fully open position so that said stored energy means returns said overload responsive means to its initial position, second means for holding said switch means in its fully open position, and second release means for releasing said switch means after said overload responsive means reaches its initial position so that said stored energy means returns said switch means to its closed position.

7. A repeating circuit interrupter having main switch means, overload responsive means in circuit with said switch means and movable from an initial position to a final position upon the occurrence of an overload current, switch opening spring means coupled to said overload responsive means for being charged and for opening said main switch means as said overload responsive means moves into its second position, said spring means being operative to return said overload responsive means to its initial position after a switch opening operation and to return said switch means to its closed position, auxiliary spring means, cam means operatively associated with said overload responsive means for extending said auxiliary spring means as said overload responsive means approaches its final position, said auxiliary spring means engaging said switch means when the latter is in its fully open position for urging said switch means toward its closed position.

8. A repeating circuit interrupter having switch means, overload responsive means in circuit with said switch means and movable from an initial position to a final position upon the occurrence of an overload current, spring means for being charged and for opening said switch means as said overload responsive means moves into its final position, said spring means being operative when charged to urge said overload responsive means to ward its initial position and said switch means toward its closed position, first latch means for holding said overload responsive means in its final position, means operatively associated with said switch means for releasing said overload responsive means when said switch means reaches its fully open position so that said spring means returns said overload responsive means to its initial position, second latch means for holding said switch means in its fully open position, and second latch release means for releasing said switch means after said overload responsive means reaches its initial position so that said spring means returns said switch means to its closed position, auxiliary spring means, cam means operatively associated with said overload responsive means for extending said auxiliary spring means, said auxiliary spring means engaging said switch means 'when the latter is in its fully open position for urging said switch means toward its closed position.

9. A repeating circuit interrupt-er having switch means, an overload coil in series with said switch means, a magnetic plunger movable from an initial position to a final position relative to said coil upon the occurrence of an overload current, linkage means coupled to said plunger and movable from an initial position to a final position upon the movement of said plunger from its initial to its final position, main spring means coupled to said linkage means and to said switch means for opening said switch means as said linkage moves into its final position, latch means for holding said switch means in its fully open position, said spring means urging the return of said plunger and said linkage means to their initial positions, means for retarding the movement of said plunger to its initial position, and latch release means for releasing said switch means after said plunger reaches its initial position, said spring means being operative to return said switch means to its closed position, auxiliary spring means, cam means operatively associated wtih said linkage means for extending said auxiliary spring means, said auxiliary spring means engaging said switch means when the latter is in its fully open position for urging said switch means toward its closed position.

10. A repeating circuit interrupter having switch means, an overload coil in series with said switch means, a magnetic plunger movable from an initial position to a final position relative to said coil upon the occurrence of an overload current, linkage means coupled to said plunger and movable from an initial position to a final position upon the movement of said plunger from its initial to its final position, spring means coupled to said linkage means and to said switch means for being charged and for opening said switch means as said linkage means moves into its final position, said spring means urging said plunger and linkage means toward their initial positions after the opening of said switch means and said switch means toward its closed position after said plunger and linkage means have returned to their initial positions, first latch means for holding said linkage means and said plunger in their final positions, means operatively associated with said switch means for releasing said linkage means when said switch means reaches its fully open position so that said plunger and linkage means are returned to their initial positions, second latch means for holding said switch means in its fully open position, and second latch release means for releasing said switch means after said plunger reaches its initial position, so that said switch means is closed.

11. A repeating circuit interrupter having switch means, an overload coil in series with said switch means, a magnetic plunger movable from an initial position to a final position relative to said coil upon the occurrence of an overload current, linkage means coupled to said plunger and movable from an initial position to a final position upon the movement of said plunger from its initial to its final position, main spring means coupled to said linkage means and to said switch means for being charged and for opening said switch means as said linkage means moves into its final position, said spring means being operative when charged to urge said plunger and linkage means toward their initial positions and said switch means toward its closed position, first latch means for holding said linkage means and said plunger in their final positions, means operatively associated with said switch means for releasing said linkage means when said switch means reaches its fully open position so that said plunger and linkage means are returned to their initial positions, second latch means for holding said switch means in its fully open position, means for retarding the movement of said plunger to its initial position, and second latch release means for releasing said switch means after said plunger reaches its initial position so that said switch means is returned to its closed position, auxiliary spring means, cam means operatively associated with said linkage means for extending said auxiliary spring means, said auxiliary spring means engaging said switch means when the latter is in its fully open position for urging said switch means toward its closed position.

12. A repeating circuit interrupter having switch means, normally inactive lockout means for effecting a continuous switch open condition, an overload coil in series with said switch means, a magnetic plunger movable from an initial position to a final position relative to said coil upon the occurrence of an overload current, hydraulic integrating means including pump means and integrating means, said pump means being coupled to said plunger for delivering a measured quantity of hydraulic fluid to said integrating means when said plunger moves to its final position, said integrating means being operative after a first predetermined number of pump operations to delay the movement of the plunger to its final position and after a second predetermined number of pump operations to actuate said lockout means, main spring means coupled to said plunger and to said switch means for being charged and opening said switch means as said plunger moves into its final position, said spring means being operative when charged to urge said plunger toward its initial position and said switch means toward its closed position, latch means for holding said switch means in its fully open position, and latch release means for releasing said switch means after said plunger reaches its initial position, so that said spring means returns said switch means to its closed position, auxiliary spring means, cam means operatively associated with said linkage means for extending said auxiliary spring means as said linkage means approaches its final position, said auxiliary spring means engaging said switch means when the latter is in its fully open position for urging said switch means toward its closed position.

13. A repeating circuit interrupter having switch means, normally inactive lockout means for effecting a continuous switch open condition, an overload coil in series with said switch means, a magnetic plunger movable from an initial position to a final position relative to said coil upon the occurrence of an overload current, hydraulic integrating means including pump means and integrating means, said pump means being coupled to said plunger means for delivering a measured quantity of hydraulic fluid to said integrating means when said plunger moves to its final position said integrating means being operative after a first predetermined number of pump operations to delay the movement of the plunger to its final position and after a second predetermined number of pump operations to actuate said lockout means, linkage means coupled to said plunger and movable from an initial position to a final position upon the movement of said plunger from its initial to its final position, main spring means coupled to said llinkage means and to said switch means being charged and for opening said switch means as said from its initial to its final position, main spring means being operative when charged to urge said plunger and linkage means toward their initial positions and said switch means toward its closed position, first latch means for holding said linkage means and said plunger in their final positions, means operatively associated with said switch means for releasing said linkage means when said switch means reaches its fully open position so that said spring means returns said plunger and linkage means to their initial positions, means for retarding the movement of said plunger to its initial position second latch means for holding said switch means in ts fully open position, and second latch release means associated with said link- 11 12 age means for releasing said switch means after said References Cited fri i relili sail sllii ii $122 10 is iissi ioiiil f UNITED STATES PATENTS s 1 c t s auxiliary spring means, cam means operatively associated 9/1922 Hulse with said linkage means for extending said auxiliary 5 3 :2 Egg spring means as said linkage means approaches its final position, said auxiliary spring means engaging said switch means when the latter is in its fully open position for BERNARD GILHEANY Prlmmy Examiner urging said switch means toward its closed position. H. BROOME, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,376 ,525 April 2 1968 Kazuo Henry Date It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10, line 53, after "position" insert a comma; line 64, "from its initial to its final" should read linkage moves into its final line 73, after "position" insert a comma; line 74, "ts" should read its Signed and sealed this 2nd day of September 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

1. A REPEATING CIRCUIT INTERRUPTER HAVING SWITCH MEANS, CONDITION RESPONSIVE MEANS IN CIRCUIT WITH SAID SWITCH MEANS AND OPERABLE FROM AN INITIAL STATE TO A FINAL STATE UPON THE OCCURRENCE OF AN ABNORMAL CIRCUIT CONDITION, SWITCH OPERATING MEANS FOR OPENING SAID SWITCH MEANS AS SAID CONDITION RESPONSIVE MEANS OPERATES TO ITS FINAL STATE, FIRST MEANS FOR HOLDING SAID CONDITION RESPONSIVE MEANS IN ITS FINAL STATE, MEANS OPERATIVELY ASSOCIATED WITH SAID SWITCH MEANS FOR RELEASING SAID CONDITION RESPONSIVE MEANS WHEN SAID SWITCH MEANS REACHES ITS FULLY OPEN POSITION, 